jsqubits

If you are new to quantum programming, then it is highly recommended that you try reading John Watrous' Quantum Information and Computation Lecture Notes. You may also wish to try reading the (work in progress) Introduction to Quantum Programming using jsqubits.

Usage -----

Online

Install using npm

You can use jsqubits in a Node application by installing jsqubits using npm.

First, make sure you have at least version 16 of Node installed.

Place the following code in myprogram.mjs. Note the .mjs extension is a way of informing Node that the program uses ES modules.

import {jsqubits} from 'jsqubits'
const result = jsqubits('|0101>').hadamard(jsqubits.ALL);
console.log(result.toString());

Run the following:

$ npm install jsqubits@2
$ node myprogram.mjs

Downloading from github

You could use jsqubits by cloning the github repository, or downloading a release from github.

First, make sure you have at least version 22 of Node installed.

Clone jsqubits

$ git clone https://github.com/davidbkemp/jsqubits.git

Place the following code in myprogram.mjs. Note the .mjs extension is a way of informing Node that the program uses ES modules.

import {jsqubits} from './jsqubits/lib/index.js'
const result = jsqubits('|0101>').hadamard(jsqubits.ALL);
console.log(result.toString());

Run your program using Node:

$ node myprogram.mjs

On your own website

Browser bundle

The GitHub repository includes dist/jsqubits.js and the smaller, minified dist/jsqubits.min.js. Copy either file next to your web page and load it with a regular script tag. Both expose the callable jsqubits global, including helpers such as jsqubits.QMath, and require no module loader.

<!DOCTYPE html>
<html>
<body>
  <p id="result"></p>
  <script src="./jsqubits.min.js"></script>
  <script>
    const qstate = jsqubits('|0>').hadamard(0).T(0);
    document.getElementById('result').textContent = qstate.toString();
  </script>
</body>
</html>

This also works when opening the page directly from the local file system. The bundles target modern browsers; they do not transpile JavaScript for legacy browsers such as Internet Explorer. They are distributed through GitHub, not included in the npm package.

Native ES modules

You can still use native ES modules directly from the lib directory:

• The page will need to be served by a web server, not just loaded from your local file system.

• You will need a copy of the contents of the lib directory on your web server.
• Your page will need to specify type="module" in the script tag used to load the jsqubits library.
• The page will not work on old versions of web browsers. It definitely won't work on Internet Explorer.

e.g. assuming you have placed the contents of lib in a directory called jsqubits that sits next to your webpage, then you could create a simple web page like this:

<html>
<body><p id="result"></p></body>
<script type="module">
  import jsqubits from './jsqubits/index.js';
  const qstate = jsqubits('|0>').hadamard(0).T(0);
  document.getElementById("result").innerHTML = qstate.toString();
</script>
</html>

See other examples in the examples directory.

TypeScript type definitions --------------------------- TypeScript type definitions for jsqubits are available:

• Node npm module: https://www.npmjs.com/package/@types/jsqubits
• Github: https://github.com/qramana/jsqubits.d.ts

Development ----------- To run the tests, you will need to install version 16 or later of Node.js (https://nodejs.org). Then use npm install to install the testing dependencies and npm test to run the specs. NOTE: The tests include an example of factoring using Shor's faction algorithm. This is non-deterministic and can take a fraction of a second or several seconds to complete.

Building the browser distribution

With Node.js 22 or later installed, run:

npm install
npm run build

Rollup generates dist/jsqubits.js and dist/jsqubits.min.js. After changing library source, run the build explicitly and commit both refreshed bundles alongside your source changes before pushing to GitHub. The simple web example in examples/simpleWebPage/index.html uses the unminified bundle.

Building is on demand only: installation, tests, npm packaging/publishing, and CI do not regenerate the bundles. Browser tests exercise the checked-in files. The clean command preserves them.

License -------

(The MIT License)

Copyright (c) 2012 David Kemp <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.